The present invention relates to a steering column assembly.
In modern vehicle construction, steering columns are implemented so that their tilt and length may be modified for comfort purposes. They may thus be set to the individual requirements of a driver. Clamping means are provided for fixing the steering column in its position. These are constructed in such a way that they block the modifiability of the position of the steering column reliably and permanently. This applies in particular for the case in which a force acting in the axial direction engages on the steering column, as in the event of an accident, for example.
In addition, the clamping means must be designed to permit, if necessary, an easy modification of the position of the steering column. A steering column of this type is known, for example, from EP 0 802 104 A1. That steering column has a bracket fixed on the vehicle, on which the clamping means are mounted in the form of lamellae. The steering column is connected to a bracket fixed to the vehicle via these clamping means. In an open position of the clamping means, the steering column can be displaced in relation to the bracket. In a closed position of the clamping means, the steering column is fixed in relation to the bracket.
In order to design steering column assemblies safely for a vehicle impact, attaching a steering column whose position is not adjustable to a bracket situated fixed to the vehicle so that, in case of an accident, an axial displacement of the steering column in relation to the bracket is made possible with energy absorption, is known. For this purpose, for example, reference is made to DE 37 20 320 A1 disclosing a steering column assembly having a bracket situated fixed on the vehicle. Furthermore, also described is a nonadjustable steering column, which is connected via a clip to the bracket. Clip and bracket are connected to one another via bolts. The bolts engage in oblong holes introduced into the clip, which allow displacement of the clip in relation to the bracket while absorbing energy in case of an accident. How the clip is fixed in relation to the bracket during normal use of the steering column assembly is not described.
A steering column assembly for motor vehicles which forms the species is disclosed in EP 0 949 136 B1.
An object of the present invention is to provide a steering column assembly in which, while maintaining known comfort functions, the safety of vehicle passengers is increased and reliable use of the steering column assembly is ensured.
This object has been achieved according to the present invention by a steering column assembly in which the energy absorbing element is guided along the bracket, or on a deformation element on the bracket during displacement, and is deformed at the same time.
The foregoing object has been achieved according to the present invention by a steering column assembly having a bracket situated fixed on the vehicle, and a steering column which is implemented so its tilt and length may be modified for comfort reasons. In addition, a clamping mechanism is provided for fixing the steering column in its position. In order to increase the safety of vehicle passengers in case of a crash, a bracket slide is provided between the bracket situated fixed on the vehicle and the steering column having the clamping mechanism, which is connected to the bracket, so that a linear displacement of the bracket slide along the bracket is possible. Furthermore, an energy absorbing element is provided, which is situated to absorb energy in the event of a displacement of the bracket slide in relation to the bracket. Thereby, the safety of vehicle passengers is increased in the event of an accident, because, in addition to displacement of the steering column, impact energy is additionally absorbed.
The steering column assembly according to the present invention particularly has the advantage that the bracket receives the bracket slide and all functional elements of the clamping mechanism and therefore is insensitive to external influences, such as, for example, tolerances in the mounting and the vehicle body support structure to which the bracket is attached. These tolerances therefore have no influence on the crash function.
In the steering column assembly according to the present invention, the energy absorption occurs on the basis of deformation work of the energy absorbing element. Energy absorption via deformation work is well-known in the field of automobile technology from other areas. Because of this, simple implementation is possible, since the experience of other fields may be used.
The energy absorbing element may be implemented as, for example, a wire. Other forms are also contemplated, such as a sheet-metal strip.
Energy absorption may occur via an energy absorbing element if two parts are moved in relation to one another. According to a first embodiment variation, the bracket slide engages on the wire during its displacement and carries the wire along. If the wire is guided along and deformed on a further object, such as the bracket, at the same time, energy may be absorbed in a simple way. It is contemplated to situate a reforming element on the bracket for this purpose.
According to a further embodiment of the present invention, the energy absorption only occurs after the bracket slide has already been displaced over a specific path in relation to the bracket. This provides the advantage that the energy level at the instant of the disengagement of the bracket slide from the bracket is minimized, so that no unacceptable load spikes occur for the vehicle passengers.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.